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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/regulator/max8952.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/regulator/max8952.c')
| -rw-r--r-- | drivers/regulator/max8952.c | 339 |
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/regulator/max8952.c b/drivers/regulator/max8952.c new file mode 100644 index 000000000..f8b91a570 --- /dev/null +++ b/drivers/regulator/max8952.c @@ -0,0 +1,339 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * max8952.c - Voltage and current regulation for the Maxim 8952 + * + * Copyright (C) 2010 Samsung Electronics + * MyungJoo Ham <myungjoo.ham@samsung.com> + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/i2c.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/regulator/driver.h> +#include <linux/regulator/max8952.h> +#include <linux/gpio/consumer.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/regulator/of_regulator.h> +#include <linux/slab.h> + +/* Registers */ +enum { + MAX8952_REG_MODE0, + MAX8952_REG_MODE1, + MAX8952_REG_MODE2, + MAX8952_REG_MODE3, + MAX8952_REG_CONTROL, + MAX8952_REG_SYNC, + MAX8952_REG_RAMP, + MAX8952_REG_CHIP_ID1, + MAX8952_REG_CHIP_ID2, +}; + +struct max8952_data { + struct i2c_client *client; + struct max8952_platform_data *pdata; + struct gpio_desc *vid0_gpiod; + struct gpio_desc *vid1_gpiod; + bool vid0; + bool vid1; +}; + +static int max8952_read_reg(struct max8952_data *max8952, u8 reg) +{ + int ret = i2c_smbus_read_byte_data(max8952->client, reg); + + if (ret > 0) + ret &= 0xff; + + return ret; +} + +static int max8952_write_reg(struct max8952_data *max8952, + u8 reg, u8 value) +{ + return i2c_smbus_write_byte_data(max8952->client, reg, value); +} + +static int max8952_list_voltage(struct regulator_dev *rdev, + unsigned int selector) +{ + struct max8952_data *max8952 = rdev_get_drvdata(rdev); + + if (rdev_get_id(rdev) != 0) + return -EINVAL; + + return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000; +} + +static int max8952_get_voltage_sel(struct regulator_dev *rdev) +{ + struct max8952_data *max8952 = rdev_get_drvdata(rdev); + u8 vid = 0; + + if (max8952->vid0) + vid += 1; + if (max8952->vid1) + vid += 2; + + return vid; +} + +static int max8952_set_voltage_sel(struct regulator_dev *rdev, + unsigned selector) +{ + struct max8952_data *max8952 = rdev_get_drvdata(rdev); + + if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) { + /* DVS not supported */ + return -EPERM; + } + + max8952->vid0 = selector & 0x1; + max8952->vid1 = (selector >> 1) & 0x1; + gpiod_set_value(max8952->vid0_gpiod, max8952->vid0); + gpiod_set_value(max8952->vid1_gpiod, max8952->vid1); + + return 0; +} + +static const struct regulator_ops max8952_ops = { + .list_voltage = max8952_list_voltage, + .get_voltage_sel = max8952_get_voltage_sel, + .set_voltage_sel = max8952_set_voltage_sel, +}; + +static const struct regulator_desc regulator = { + .name = "MAX8952_VOUT", + .id = 0, + .n_voltages = MAX8952_NUM_DVS_MODE, + .ops = &max8952_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, +}; + +#ifdef CONFIG_OF +static const struct of_device_id max8952_dt_match[] = { + { .compatible = "maxim,max8952" }, + {}, +}; +MODULE_DEVICE_TABLE(of, max8952_dt_match); + +static struct max8952_platform_data *max8952_parse_dt(struct device *dev) +{ + struct max8952_platform_data *pd; + struct device_node *np = dev->of_node; + int ret; + int i; + + pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL); + if (!pd) + return NULL; + + if (of_property_read_u32(np, "max8952,default-mode", &pd->default_mode)) + dev_warn(dev, "Default mode not specified, assuming 0\n"); + + ret = of_property_read_u32_array(np, "max8952,dvs-mode-microvolt", + pd->dvs_mode, ARRAY_SIZE(pd->dvs_mode)); + if (ret) { + dev_err(dev, "max8952,dvs-mode-microvolt property not specified"); + return NULL; + } + + for (i = 0; i < ARRAY_SIZE(pd->dvs_mode); ++i) { + if (pd->dvs_mode[i] < 770000 || pd->dvs_mode[i] > 1400000) { + dev_err(dev, "DVS voltage %d out of range\n", i); + return NULL; + } + pd->dvs_mode[i] = (pd->dvs_mode[i] - 770000) / 10000; + } + + if (of_property_read_u32(np, "max8952,sync-freq", &pd->sync_freq)) + dev_warn(dev, "max8952,sync-freq property not specified, defaulting to 26MHz\n"); + + if (of_property_read_u32(np, "max8952,ramp-speed", &pd->ramp_speed)) + dev_warn(dev, "max8952,ramp-speed property not specified, defaulting to 32mV/us\n"); + + pd->reg_data = of_get_regulator_init_data(dev, np, ®ulator); + if (!pd->reg_data) { + dev_err(dev, "Failed to parse regulator init data\n"); + return NULL; + } + + return pd; +} +#else +static struct max8952_platform_data *max8952_parse_dt(struct device *dev) +{ + return NULL; +} +#endif + +static int max8952_pmic_probe(struct i2c_client *client) +{ + struct i2c_adapter *adapter = client->adapter; + struct max8952_platform_data *pdata = dev_get_platdata(&client->dev); + struct regulator_config config = { }; + struct max8952_data *max8952; + struct regulator_dev *rdev; + struct gpio_desc *gpiod; + enum gpiod_flags gflags; + + int ret = 0; + + if (client->dev.of_node) + pdata = max8952_parse_dt(&client->dev); + + if (!pdata) { + dev_err(&client->dev, "Require the platform data\n"); + return -EINVAL; + } + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) + return -EIO; + + max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data), + GFP_KERNEL); + if (!max8952) + return -ENOMEM; + + max8952->client = client; + max8952->pdata = pdata; + + config.dev = &client->dev; + config.init_data = pdata->reg_data; + config.driver_data = max8952; + config.of_node = client->dev.of_node; + + if (pdata->reg_data->constraints.boot_on) + gflags = GPIOD_OUT_HIGH; + else + gflags = GPIOD_OUT_LOW; + gflags |= GPIOD_FLAGS_BIT_NONEXCLUSIVE; + /* + * Do not use devm* here: the regulator core takes over the + * lifecycle management of the GPIO descriptor. + */ + gpiod = gpiod_get_optional(&client->dev, + "max8952,en", + gflags); + if (IS_ERR(gpiod)) + return PTR_ERR(gpiod); + if (gpiod) + config.ena_gpiod = gpiod; + + rdev = devm_regulator_register(&client->dev, ®ulator, &config); + if (IS_ERR(rdev)) { + ret = PTR_ERR(rdev); + dev_err(&client->dev, "regulator init failed (%d)\n", ret); + return ret; + } + + max8952->vid0 = pdata->default_mode & 0x1; + max8952->vid1 = (pdata->default_mode >> 1) & 0x1; + + /* Fetch vid0 and vid1 GPIOs if available */ + gflags = max8952->vid0 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; + max8952->vid0_gpiod = devm_gpiod_get_index_optional(&client->dev, + "max8952,vid", + 0, gflags); + if (IS_ERR(max8952->vid0_gpiod)) + return PTR_ERR(max8952->vid0_gpiod); + gflags = max8952->vid1 ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW; + max8952->vid1_gpiod = devm_gpiod_get_index_optional(&client->dev, + "max8952,vid", + 1, gflags); + if (IS_ERR(max8952->vid1_gpiod)) + return PTR_ERR(max8952->vid1_gpiod); + + /* If either VID GPIO is missing just disable this */ + if (!max8952->vid0_gpiod || !max8952->vid1_gpiod) { + dev_warn(&client->dev, "VID0/1 gpio invalid: " + "DVS not available.\n"); + max8952->vid0 = 0; + max8952->vid1 = 0; + /* Make sure if we have any descriptors they get set to low */ + if (max8952->vid0_gpiod) + gpiod_set_value(max8952->vid0_gpiod, 0); + if (max8952->vid1_gpiod) + gpiod_set_value(max8952->vid1_gpiod, 0); + + /* Disable Pulldown of EN only */ + max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60); + + dev_err(&client->dev, "DVS modes disabled because VID0 and VID1" + " do not have proper controls.\n"); + } else { + /* + * Disable Pulldown on EN, VID0, VID1 to reduce + * leakage current of MAX8952 assuming that MAX8952 + * is turned on (EN==1). Note that without having VID0/1 + * properly connected, turning pulldown off can be + * problematic. Thus, turn this off only when they are + * controllable by GPIO. + */ + max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0); + } + + max8952_write_reg(max8952, MAX8952_REG_MODE0, + (max8952_read_reg(max8952, + MAX8952_REG_MODE0) & 0xC0) | + (pdata->dvs_mode[0] & 0x3F)); + max8952_write_reg(max8952, MAX8952_REG_MODE1, + (max8952_read_reg(max8952, + MAX8952_REG_MODE1) & 0xC0) | + (pdata->dvs_mode[1] & 0x3F)); + max8952_write_reg(max8952, MAX8952_REG_MODE2, + (max8952_read_reg(max8952, + MAX8952_REG_MODE2) & 0xC0) | + (pdata->dvs_mode[2] & 0x3F)); + max8952_write_reg(max8952, MAX8952_REG_MODE3, + (max8952_read_reg(max8952, + MAX8952_REG_MODE3) & 0xC0) | + (pdata->dvs_mode[3] & 0x3F)); + + max8952_write_reg(max8952, MAX8952_REG_SYNC, + (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) | + ((pdata->sync_freq & 0x3) << 6)); + max8952_write_reg(max8952, MAX8952_REG_RAMP, + (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) | + ((pdata->ramp_speed & 0x7) << 5)); + + i2c_set_clientdata(client, max8952); + + return 0; +} + +static const struct i2c_device_id max8952_ids[] = { + { .name = "max8952" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max8952_ids); + +static struct i2c_driver max8952_pmic_driver = { + .probe = max8952_pmic_probe, + .driver = { + .name = "max8952", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .of_match_table = of_match_ptr(max8952_dt_match), + }, + .id_table = max8952_ids, +}; + +static int __init max8952_pmic_init(void) +{ + return i2c_add_driver(&max8952_pmic_driver); +} +subsys_initcall(max8952_pmic_init); + +static void __exit max8952_pmic_exit(void) +{ + i2c_del_driver(&max8952_pmic_driver); +} +module_exit(max8952_pmic_exit); + +MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver"); +MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); +MODULE_LICENSE("GPL"); |
